[[PTStitcher]] has the same output file format options as [[nona]] plus a few more, notably

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'''PTStitcher''' can create [[Photoshop]] native [[PSD]] files. Also note that the [[QTVR]]

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option only generates [[Cylindrical Projection]] output, don't use this as there are better

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[[QTVR tools]].

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[[Category:Software:Hugin]]

[[Category:Software:Hugin]]

Revision as of 21:48, 6 June 2007

The Stitcher-Tab in hugin

The Stitcher-Tab in hugin

The rest of hugin is all about setting up the project and aligning images, the Stitcher tab is where
the final output file is created.

Panorama

Here you can set the output Projection of your project, there are lots
to choose from, each with different advantages and disadvantages:

Rectilinear, this is the same projection as a photo taken with a 'normal' camera and lens. Use this if you are just stitching a handful of photographs together with a narrow Field of View or correcting perspective in a single shot.

Panorama, actually a simple Cylindrical Projection as used by traditional rotating panoramic cameras. A good projection for printing a 360 degree panorama, though you may prefer Mercator Projection.

Equirectangular, the all purpose format for representing an entire spherical scene. It covers 360 degrees horizontally as well as the zenith and nadir.

Fisheye, the same projection as a photo taken with a fisheye lens. Better for representing a wide Field of View than rectilinear, but in many cases Stereographic Projection gives less distortion than simple fisheye.

Stereographic, a conformal fisheye image. Objects in a stereographic image keep the same shape and show less distortion than simple fisheye.

Mercator, a conformal cylindrical image. A good projection for printing a 360 degree panorama.

Field of View

This is the horizontal and vertical angle of view of the output image,
clicking Calculate Field of View will shrink or enlarge the field of view of the
output to fit the arrangement of the input images - The Fit button in the
Hugin Preview window does the same thing.

into a layered photoshop file, creates a PSD file for editing in Photoshop with each input image on a separate layer, requires PTStitcher.

Panorama Image Size

Set the width and height of your output panorama in pixels. Calculate Optimal Size will estimate
a size that has about the same resolution as your input images.

Some examples: a three megapixel image has pixel dimensions of 2048 x 1536, an A4 print at 300 pixels per inch will
have a pixel size of 3500 x 2480, a full screen spherical Equirectangular Projection image will have pixel
dimensions of 6000 x 3000 or greater and a gigapixel image has a pixel size of 32768 x 32768.

Note that the interpolation used by hugin doesn't handle downsampling very well, so output images smaller
than about half the size of the Optimal Size will show aliasing artefacts. If you want to create high quality
small images, it is better to create an Optimal Size image in hugin and downsize it later in an image editor such as the Gimp.

nona Stitching Engine

nona is the default stitching engine supplied with hugin, normally there is no need to
change this or any of the options below.

Stitching Options

Set the Interpolator (i) to change the sampling interpolation. You probably won't notice
much difference between the various options except that Nearest Neighbour is fast but with
very low quality. The default of Poly3 (bicubic) is generally good for most purposes.

The Gamma (g) sets the assumed gamma correction of the input images, this value is
used when interpolating, though the effect isn't usually obvious. Most photos from digital cameras
have a gamma somewhere between 2.0 and 2.5.

Output File options

The output image can be in one several formats:

JPG, lossy compression suitable for web/email. Blending with enblend not is available, so seams may be obvious.

TIFF, various compression options. 16bit and high dynamic range formats are supported. Blending is available via enblend (by creating temporary Multiple TIFF files and blending them into a single TIFF).

Multiple TIFF, same as TIFF except with one output file for each input photo. This format is suitable for command-line blending in enblend

Multilayer TIFF, same as Multiple TIFF except a single multilayer file is created. This can be opened in the gimp for manual blending.

HDR, Radiance RGBE format. This is a high dynamic range format which is more compact than a high dynamic range TIFF.

Cropped TIFF files are smaller and more efficient because unused parts of the image are not stored in the file. You should
always Save cropped images unless you need to open them in an image editor without Cropped TIFF support.

If Soft Blending is enabled then enblend is used for blending. In the final stitching process nona reprojects and distorts images to fit, enblend takes these images as individual TIFF files and merges them using sophisticated seam positioning and blending into a single finished TIFF file. Further enblend settings can be found in the hugin Preferences.

PTStitcher Stitching Engine

PTStitcher is the original stitching engine supplied with Panorama Tools, but now largely superceded by nona - Though you may want to use it for functionality that isn't available in nona such as morph to fit.

To use PTStitcher you need to find one of the original win32 or linux i386 binaries on one of the mirrors of Helmut Dersch's site; then place it in your $PATH, or specify the location in the hugin Preferences.

Stitching Options

exposure correction will adjust the brightness and colour of overlapping photos to reduce
the effect of variations in lighting (such as those caused by a cloud moving in front of the sun).
Don't use PTStitcher for this as hugin now provides much improved photometric correction
in the hugin Exposure tab.

fast transform (f) speeds up computationally intensive projection calculations by
interpolating positions rather than calculating them all. This results in a small, but usually
unnoticeable, quality reduction. This is most effective when remapping single images where the ouput
frame is filled, panoramas with lots of empty space or many input photos may be faster with the
nona option to Save cropped images, which generates Cropped TIFF output.

feather width performs simplistic feathering of seams between input photos, use nona and
the Soft blending with enblend option for much better (and slower) results.